Buggy code:
public class Ghost extends NPC { private static final String TXT_ROSE1 = "Hello<seq2seq4repair_space>adventurer...<seq2seq4repair_space>Once<seq2seq4repair_space>I<seq2seq4repair_space>was<seq2seq4repair_space>like<seq2seq4repair_space>you<seq2seq4repair_space>-<seq2seq4repair_space>strong<seq2seq4repair_space>and<seq2seq4repair_space>confident...<seq2seq4repair_space>" + ( "And<seq2seq4repair_space>now<seq2seq4repair_space>I'm<seq2seq4repair_space>dead...<seq2seq4repair_space>But<seq2seq4repair_space>I<seq2seq4repair_space>can't<seq2seq4repair_space>leave<seq2seq4repair_space>this<seq2seq4repair_space>place...<seq2seq4repair_space>Not<seq2seq4repair_space>until<seq2seq4repair_space>I<seq2seq4repair_space>have<seq2seq4repair_space>my<seq2seq4repair_space>_dried<seq2seq4repair_space>rose_...<seq2seq4repair_space>" + "It's<seq2seq4repair_space>very<seq2seq4repair_space>important<seq2seq4repair_space>to<seq2seq4repair_space>me...<seq2seq4repair_space>Some<seq2seq4repair_space>monster<seq2seq4repair_space>stole<seq2seq4repair_space>it<seq2seq4repair_space>from<seq2seq4repair_space>my<seq2seq4repair_space>body..." ) ; private static final String TXT_ROSE2 = "Please...<seq2seq4repair_space>Help<seq2seq4repair_space>me...<seq2seq4repair_space>Find<seq2seq4repair_space>the<seq2seq4repair_space>rose..." ; private static final String TXT_RAT1 = "Hello<seq2seq4repair_space>adventurer...<seq2seq4repair_space>Once<seq2seq4repair_space>I<seq2seq4repair_space>was<seq2seq4repair_space>like<seq2seq4repair_space>you<seq2seq4repair_space>-<seq2seq4repair_space>strong<seq2seq4repair_space>and<seq2seq4repair_space>confident...<seq2seq4repair_space>" + ( "And<seq2seq4repair_space>now<seq2seq4repair_space>I'm<seq2seq4repair_space>dead...<seq2seq4repair_space>But<seq2seq4repair_space>I<seq2seq4repair_space>can't<seq2seq4repair_space>leave<seq2seq4repair_space>this<seq2seq4repair_space>place...<seq2seq4repair_space>Not<seq2seq4repair_space>until<seq2seq4repair_space>I<seq2seq4repair_space>have<seq2seq4repair_space>my<seq2seq4repair_space>revenge...<seq2seq4repair_space>" + "Slay<seq2seq4repair_space>the<seq2seq4repair_space>_fetid<seq2seq4repair_space>rat_,<seq2seq4repair_space>that<seq2seq4repair_space>has<seq2seq4repair_space>taken<seq2seq4repair_space>my<seq2seq4repair_space>life..." ) ; private static final String TXT_RAT2 = "Please...<seq2seq4repair_space>Help<seq2seq4repair_space>me...<seq2seq4repair_space>Slay<seq2seq4repair_space>the<seq2seq4repair_space>abomination..." ; public Ghost ( ) { } @ Override public int defenseSkill ( Char enemy ) { } @ Override public String defenseVerb ( ) { } @ Override public float speed ( ) { } @ Override protected Char chooseEnemy ( ) { } @ Override public void damage ( int dmg , Object src ) { } @ Override public void add ( Buff buff ) { } @ Override public boolean reset ( ) { } @ Override public void interact ( ) { } @ Override public String description ( ) { } private static final HashSet < Class < ? > > IMMUNITIES = new HashSet < Class < ? > > ( ) ; @ Override public HashSet < Class < ? > > immunities ( ) { } public static class Quest { private static boolean spawned ; private static boolean alternative ; private static boolean given ; private static boolean processed ; private static int depth ; private static int left2kill ; public static Weapon weapon ; public static Armor armor ; public static void reset ( ) { } private static final String NODE = "sadGhost" ; private static final String SPAWNED = "spawned" ; private static final String ALTERNATIVE = "alternative" ; private static final String LEFT2KILL = "left2kill" ; private static final String GIVEN = "given" ; private static final String PROCESSED = "processed" ; private static final String DEPTH = "depth" ; private static final String WEAPON = "weapon" ; private static final String ARMOR = "armor" ; public static void storeInBundle ( Bundle bundle ) { } public static void restoreFromBundle ( Bundle bundle ) { } public static void spawn ( SewerLevel level ) { <START_BUG> if ( ( ( ( ! ( Dungeon . isTutorial ) ) && ( ! ( Ghost . Quest . spawned ) ) ) && ( ( ( Dungeon . depth ) > 1 ) && ( ( Random . Int ( ( 5 - ( Dungeon . depth ) ) ) ) == 0 ) ) ) || ( ( Dungeon . template ) != null ) ) { <END_BUG> Ghost ghost = new Ghost ( ) ; do { ghost . pos = level . randomRespawnCell ( ) ; } while ( ( ghost . pos ) == ( - 1 ) ) ; level . mobs . add ( ghost ) ; Actor . occupyCell ( ghost ) ; Ghost . Quest . spawned = true ; Ghost . Quest . alternative = ( Random . Int ( 2 ) ) == 0 ; if ( ! ( Ghost . Quest . alternative ) ) { Ghost . Quest . left2kill = 8 ; } Ghost . Quest . given = false ; Ghost . Quest . processed = false ; Ghost . Quest . depth = Dungeon . depth ; do { Ghost . Quest . weapon = ( ( Weapon ) ( Generator . random ( Generator . Category . WEAPON ) ) ) ; } while ( ( Ghost . Quest . weapon ) instanceof MissileWeapon ) ; if ( Dungeon . isChallenged ( NO_ARMOR ) ) { Ghost . Quest . armor = ( ( Armor ) ( new ClothArmor ( ) . degrade ( ) ) ) ; } else { Ghost . Quest . armor = ( ( Armor ) ( Generator . random ( Generator . Category . ARMOR ) ) ) ; } for ( int i = 0 ; i < 3 ; i ++ ) { Item another ; do { another = Generator . random ( Generator . Category . WEAPON ) ; } while ( another instanceof MissileWeapon ) ; if ( ( another . level ) > ( Ghost . Quest . weapon . level ) ) { Ghost . Quest . weapon = ( ( Weapon ) ( another ) ) ; } another = Generator . random ( Generator . Category . ARMOR ) ; if ( ( another . level ) > ( Ghost . Quest . armor . level ) ) { Ghost . Quest . armor = ( ( Armor ) ( another ) ) ; } } Ghost . Quest . weapon . identify ( ) ; Ghost . Quest . armor . identify ( ) ; } } public static void process ( int pos ) { } public static void complete ( ) { } } public static class FetidRat extends Mob { @ Override public int damageRoll ( ) { } @ Override public int attackSkill ( Char target ) { } @ Override public int dr ( ) { } @ Override public int defenseProc ( Char enemy , int damage ) { } @ Override public void die ( Object cause ) { } @ Override public String description ( ) { } private static final HashSet < Class < ? > > IMMUNITIES = new HashSet < Class < ? > > ( ) ; @ Override public HashSet < Class < ? > > immunities ( ) { } } }

Fix:
if ( ( ( ! ( Dungeon . isTutorial ) ) && ( ! ( Ghost . Quest . spawned ) ) ) && ( ( ( ( Dungeon . depth ) > 1 ) && ( ( Random . Int ( ( 5 - ( Dungeon . depth ) ) ) ) == 0 ) ) || ( ( Dungeon . template ) != null ) ) ) {